This proposal focuses on the detection of HIV antigens in blood. The antigen detection system will involve optimization of a sandwich type capture ELISA by investigation of a large set of antiviral antibodies coupled with the development of novel signal amplification techniques called "enzyme channeling" and "cycling reactions." Immunoglobulins will be obtained from human plasma and affinity purified. Antibodies will be similarly prepared from rabbits immunized with lysed virions and from rabbits immunized with viral components (p24 and envelope glycoproteins) obtained from viral purifications, DNA cloning and peptide synthesis. Monoclonal antibodies will also be prepared. Suitable noncompetitive antigens as references and for specificity using human blood proteins and unrelated virus controls. Extensive effort will then be placed on the enhancement of the immunoassay by innovative techniques which exploit coupled enzyme reactions in both the solid and liquid phases of the assay system. Based on similar assays that have been developed, the investigators project the development of an extraordinarily simple, rapid and sensitive test.